The present invention relates to a conveying system and, more particularly, to a conveying system for transportation and storage of trestle frames of scaffolds, to be utilized in the upright position, with a lower platform-like frame of sheet steel or the like having receiving openings for the forks of forklift trucks, and with holding means for the trestle frames.
Parts of scaffolds have long been stored and transported essentially in a prone position on holding devices of the type of transport platforms or transport pallets by perpendicularly extending fixation elements. With such a storage and transportation, the holding devices can be picked up by forklifts and transferred, or can be transferred in a suspended condition with other hoisting means with the aid, for example, ropes, chains, or the like. This type of storage and conveyance is also used for trestle frames designed as coherent frames of certain scaffolding systems. In these structures, respectively two scaffold poles to be placed vertically are combined into the trestle frame by an upper cross connection supporting the scaffold floor, and a lower cross connection which normally also prevents a lifting off of the scaffold floors and, optionally, these poles are provided with further auxiliary means. Such trestle frames are of a relatively large weight and during and assembly and disassembly of the scaffolding at a building site, considerable use of force is required by scaffold assemblers who perform this work exclusively manually.
To facilitate labor and to render transportation and storage more practical in, for example, DOS No. 3,536,914.0 A 1, a conveyance platform construction is proposed which includes plug-in receptacles for the tube ends of trestle frames. In this arrangement, vertically projecting tenons or pipes are provided into which the toothed ends of the trestle frames are threaded, or onto which the open tube ends are placed. This proposed construction has not become too popular because the threading operation is very difficult.
It has also been verbally suggested to include a profiled rails of a certain minimum thickness to be equipped with bores and arranged mutually in pairs above the profile frame of the transport pallet, and to be connected to the transport pallet. The steel tube posts or trestle frames are then to be passed with their tube ends through the rail bores until they rest with their tube ends on the steel profile frame. However, this suggestion does not lead itself to practical realization since here again a threading operation is required which demands a great amount of skill because the plug-in receptacles must be adapted with relatively high accuracy to the tube diameter so that the trestle frames are held perpendicularly in the plug-in receptacles. Additionally, this theoretical suggestion does not take into account the cross connections of the trestle frames in the lower zone.
Due to the great weight of each individual trestle frame, threading of the ends of the trestle frame tubes into the openings or placing such tubes onto tenons is difficult and requires a great amount of retaining force during this operation. The provision of closed openings and, respectively, the attachment of a large number of tube ends or pins requires considerable manufacturing expenditure or suitable expensive welding devices. Although the conveying platform is equipped with plug-in and retaining means for forks of forklifts, the proposed constructions are merely such that the forks are to be inserted from one side. Loading onto trucks and practical stacking in storage sheds and carrying to building sites require the receptacles for the forks of forklift trucks be disposed in such a manner that they can be engaged not only from opposite sides.
In, for example, French reference No. A1 2,285,308, a frame work especially for intra-company transportation and storage of workpieces to be machined such as shafts with gear wheels and the like is proposed which includes corner columns with auxiliary stacking means and laterally extending, horizontal stringers. The stringers include perforations on one side thereof extending in a horizontal surface into which ends of workpieces can be placed. On the other side, a holding rail is mounted which includes upwardly open recesses at relatively large mutual spacings, with the recesses being engaged by partial areas of the elongated workpieces, such as shaft ends and the like, which are supported on the other side. This proposed arrangement is not suitable for vertical placement of trestle frames for scaffolds, and does not yield any suggestions in this respect.
DOS No. 2,033,514 proposes a process and apparatus for building of rooms, especially a living space, wherein entire building walls are transported. For this purpose, insert mountings are provided for vertical retention, satisfying the conditions in case of especially heavy building components. Such building components cannot be retained, or at least not alone, in the region of the bottom end. In this respect, the auxiliary means dealt with therein are unsuitable for an orderly depositing of trestle frames of scaffolds in conveying means of the type provided for by the present invention.
The aim underlying the present invention essentially resides in providing a conveying system for trestle frames wherein the trestle frames can be inserted and securely retained in an easy manner, within a short period of time, and with a minor expenditure of lifting force, and wherein the manufacture thereof is possible from parts that can be easily worked and with little expenditure.
According to advantageous features of the present invention, holding means for the upright retention of the trestle frames are formed by rack-shaped holding rails arranged in pairs and engaging with their teeth beside the lower tube ends and, respectively, the lower cross connections of the trestle frames, wherein the lower holding rails lie within the tube ends and the lateral rack rails with inwardly pointing lateral rack teeth lying there above at a suitable distance of preferably about 12-25 cm are located so that the inner spacing of the holding recesses corresponds to the outer spacing of the scaffold poles of the trestle frames.
A thus constructed transport system in the form cf a conveyor pallet is built up of a few parts and formed in a simple manner by punching, bending, chamfering and/or rolling and welded together in s simple, fast and secure fashion. By virtue of a low expenditure for material and a relatively low weight, this transport system exhibits great stability and, above all, permits rapid introduction of a plurality of trestle frames, to be used in upright condition, into its holding device, a removal of such frames quickly from such devices, installation of the same in the same position, and also makes it possible to transfer these frames in a relatively large number by suitable transport units to locations where they are needed or where they are supposed to be stored.
Moreover, with this arrangement, the troublesome threading operations are eliminated, and the trestle frames can be sensibly transported just as other scaffold components and can be maintained ready together with the other scaffold components or can be stored therewith.
In accordance with further features of the present invention, holding means are included for the inserted trestle frames, with the holding means being movable over the cross connections and lying with their lower holding surfaces at a spacing above the supporting faces of the holding rails corresponding to the height of top edges of the lower cross connections of the inserted trestle frames. Thereby the trestle frames can be firmly connected with the conveying system after insertion so that the entire parcel of trestle frames and conveying systems can be suspended in an upper zone on a hoisting unit such as, for example, a crane or the like and, consequently, stable transport conditions are realized.
In accordance with still further advantageous features of the present invention, the lower holding rails are bent upwards along inner edges of holding and guide plates extending up to longitudinal sidewalls and running substantially horizontally, with the bottom surfaces thereof extending at a level of the top edges of the recesses for accommodating the forks of a forklift. Thereby, in addition to lending great stability to the entire transport system, the introduction of the forks of the forklifts is substantially facilitated because the forks cannot get caught at the edges of openings formed freely out of the surface areas.
Advantageously, in accordance with the present invention, the holding teeth of the lower holding rails are fashioned as rectangular tenons formed by punching out holding recesses along rims of vertically extending inner walls of the longitudinally extending supports.
Preferably, the upper lateral holding rack rails are fashioned as separately produced longitudinal support components bent into U-shaped profiles or formed from U-shaped profiles, with the upper horizontal legs being constructed as later rack rails that are open toward an inside of the trestle frame and provided with closely just opposed holding recesses shaped as semicircles or divided circles having a diameter corresponding substantially to a diameter of the scaffold poles.
In accordance with still further features of the present invention, the upper end holding plates are welded with their lower lateral end zones at the end phase in front of the lower longitudinal supports and are welded in the zone of there upper outward corners at an end face in front of the upper profile holding rails.
Advantageously, according to the present invention, vertical connectors are provided between the lower longitudinal supports and the upper profile holding rails, with the upper and holding plates including, in a region of there ends, perforations for enabling engagement with at least one of hooks, ropes, and chains. Advantageously, the upper holding plates include recess means in a center thereof for reducing a weight thereof and at least a central grasping apentive for enabling a manual transport.
Advantageously, at least one identically central cross support is provided at a distance from lower cross struts provided at the respective ends of the longitudinally extending supports, with a distance corresponding to a length of forks of the forklifts.
In accordance with the present invention, the longitudinally extending supports include preferably in an outward bottom zone respectively one longitudinally extending outwardly rounded supporting rib formed by a double bending. Advantageously, a top portion of outer walls of each of the longitudinal supports include reinforcing legs that are bent twice toward an inside of the longitudinal supports.
Furthermore, in accordance with the present invention, holding means are provided for the inserted trestle frames which can be placed over the cross connections and which lie with their lower holding surfaces above the supporting faces of the lower holding rails at a predetermined distance corresponding to a height of the upper edges of the lower cross connections of the inserted trestle frames.
Advantageously, the holding means are constituted by holding bars extending through the transport pallet in the direction of the lower holding rails and the upper lateral holding rack rails.
Bearing bores are provided for accommodating ends of the holding bars, with the bearing bores being formed in the inside walls.
According to the present invention, the holding bars include at both ends thereof safety hooks which are bent so as to point in opposite directions, with the bearing bores being formed in the inside walls as horizontally extending slotted holes having a size sufficient to accommodate the safety hooks.
According to the present invention, the lower holding rails are bent upwardly on the inner edges of holding and guide rails extending up to the longitudinal side walls and running substantially horizontally, their bottom surfaces extending at a level of the top edges of the fork cutouts.
The longitudinally extending sidewalls include, in accordance with the present invention, at upper edges thereof the inwardly directed lateral rack teeth and at lower edges thereof bent-away bottom supporting legs, with the holding and guide plates being welded in place directly above the fork cutouts.
Preferably, according to the present invention, the end side walls are inserted between end side legs bent at an end side away from the longitudinal side walls and are welded to these legs.
Advantageously, according to the present invention, the transport pallets are provided in the edge and/or corner areas of the upper and/or lower surfaces with stacking aids for the empty state, with the aids being adapted to be brought in too mutual engagement in the vertical direction and positively preventing lateral movement.
Additionally, according to still further features of the present invention, retaining means for holding the frames in the standing or upright positions are constructed combwise and engage both onto and into from the outside and they are constructed, over a length that prevents tipping as a tilt preventer engaging the frame from below.
The above and other objects, features, and advantageous of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings which show, for the purpose of illustration only, several embodiments in accordance with the present invention.